On March 31, the Supreme Court of the United States will hear arguments in Alice Corp. v. CLS Bank, a case that will, at the very least, clear up case law from the federal circuit and could conceivably upend the software industry as we know it.

Fortune recently published the 2013 list of top 10 patent troll targets, which include AT&T, fighting 70 active cases as of the publication date. Next in line is Google, which was hit with 43 suits last year.

They are among 19 companies that told the EU in a letter to take action to limit the ability of companies that hold patents as their primary source of income from using the legal system to extort money out of other businesses.